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Monolayer Doping (MLD) is a technique involving the fmmation of a self-assembled dopant-containing layer on the substrate. The dopant is subsequently incorporated into the substrate by annealing, fmming a diffused region. Following MLD, samples were capped with silicon dioxide and rapid the1mal annealed (RTA). In this work, gallium doping using MLD has been demonstrated. Gallium containing compound Tris (2,4 pentanedionato) gallium(III) was synthesized, and shown to be suitable for monolayer doping silicon subsa-ates and deposited thin film polysi!icon. Seconda1y ion mass spectroscopy (SIMS) and spreading resistance probe (SRP) measurements were performed to determine the dopant profiles and dopant elecu-ical activation. TI1ese results showed that a dose of l.6*1015 atoms/cm2 was received, and the gallium dopant produced a 0.2 µm junction in 11-type silicon. For polysilicon, tlle entire 0.4 µm film was evenly doped, witll a concenu-ation greater than 1019 atoms/cm3 tllroughout. 

A conformal and controlled semiconductor doping is needed for applications in next generation nanoscale devices,low contact resistivity metal semiconductor junctions such as selective emitters in solar cells. Molecular monolayer doping (MLD) in silicon is a novel technique based on the formation of self-assembled monolayer of dopant – containing molecules on surface of crystalline silicon, followed by rapid thermal anneal. The technique is capable of forming ultra-shallow junctions with high atomic accuracy and minimum defects in silicon. A container and process was developed which successfully doped 6 in. diameter silicon wafers using MLD for the in-house CMOS fabrication facility. The phosphorus monolayer is grafted on hydrogen terminated p-type silicon followed by rapid thermal anneal. Average sheet resistance ~670 Ω/sq. and junction depth ~25 nm are achieved. N + P junctions are fabricated using MLD and current-voltage characteristics are measured and analyzed using unified diode model. 

We report doping of thin (~60 nm) amorphous silicon (a-Si) on glass substrate to form n + polycrystalline silicon on glass in selective regions using Monolayer doping (MLD) via Flash Lamp Annealing (FLA). The phosphorus monolayer was formed on the exposed regions of SiO2 patterned a-Si, through functionalization with chemically bound Diethyl vinylphosphonate (DVP) dopant molecules. The samples were capped with SiO2 and annealed using a single xenon flash pulse (5.0 J/cm2, 250 μs) to simultaneously crystallize a-Si, incorporate and activate phosphorus dopants. SIMS results show an average concentration of 8x1019 cm−3 in the 60 nm of thin silicon on glass. Electrical results show a resistivity of ~6.60x10−2 Ω.cm in doped regions. N-channel field effect transistor devices are successfully demonstrated using this MLD-FLA technique.